But by saying that, you would have to assume that your statement is not yet a rule, so with that you can't make any assumptions about the future.
Pretty much true.Im more than likely sure how we will see Brock and Dawn appear again,and i believe how May and Misty might return at some point as well.
If anything for May because of possible RS remakes and with Misty because of being part of original trio with many things being left unresolved and uncleared in her story(like goal of water master for which gym isnt enough).We can see with many gym leaders(like Fantina,Wallace,Cilan etc)how they leave gym to travel to improve their skill,enter competitions,catch new pokemon and learn more so its definitely not farfetched to expect same thing from Misty.
How was Brock written off the show for ever? He took an occupation as a doctor. In Unova, there's plenty of doctors roaming around. He could be there to attent a special meeting or something.
Agreed,i could definitely see Brock traveling to Unova with purpose of gaining some knowledge and learning new methods of pokemon healing from other doctors there which could help him in future study.H can also pout to us already gathered knowledge by dealing with crisis and showing how much h improved when curing and taking care of pokemon.
Doctors or those who attempt to become one sometimes tend to travel to expand horizons and enrich their knowledge so Brock coming in Unova is not so farfetched to expect.
As for Dawn i guess she has chance to appear in BW getting some follow up and how her journey in Hoenn went,though im not sure when and if it will happen.Since contests apparently dont exist there,best bet could be in trying to promote concept among people in Unova.
I think its safe to say Brock will get an appearance really later on, probably after Unova is over. We of course know he'll never be part of the main cast again, but he was there far too long to not at least give him an update on his doctor studies went.
Do we know for sure how Brock will never be part of main cast again,or this is only assumption?
With Brock you never know seeing how he was already written out once coming back for second ride.